Orthodontic anchorage



ma ma 25, 1936.. R. E. IRISH ORTHODONTIC ANCHORAGE Filed Oct. 31, 1932fag; a

Fatented Feb. 25, I936 UNITED STATES PAT'E NT OFFICE 5 Claims.

il-his invention relates to an orthodontic anchorage-ofthe :type inwhioha wire is connected with a tooth by the insertion of the wire, or aplug carried "thereby, into a socket mounted on a band-carried by thetooth.

It is .of primary importance that the engagement between :the'plugcarried by the wire, and :the :socket or sheath mounted on the band .be:suchas to minimize :the possibility of accidental withdrawal :ofthe-plug. Variousforms of inter- :engagement between the plug and thesheath thave zheen proposed :to efiect this general object. 51 havediscovered that .a :firm engagement between ;;plug and sheath is bestobtained by a complexity of structure which increases the-frictien-.,proclucin;g area of contact between the ,parts, andiw-hichgives an engagement resisting looseningzmovement :of the plug in thesocket.

i'Ihe :area within which this desirable complexityrmust be pomprised .isvery restricted, because ofzthenserto which .the apparatus is put, andfor till 3162 5011, soiaras 1am aware, complexity of prossesectionalcontour or :plug and :sheath has mot heretofore been successfullyattempted.

@I have, however, devised .a specialized plug and sheath contour which,.when carefully prenared, provides great complexity of cross-sec-.ztiona-l contour ,and adequate strength within a minimizedcross-sectional area.

A 'Vfurther, and specific, object of my invention :is-obta-ined by.making lengths .of finished shaftiug andtlengths of :tube, which areboth of unietorm cross-sectional contour and area through their length,so that they may be prepared for .use mer ly by cutting them into piecesof suit- :abledength. .Plugs and sockets of tapered form, .or which areotherwise complicated longitudi- .-na.ll;y rather than transversely oftheir axes, garesentprohibitive difficulties in manufacture.

:In the accompanying drawing Figure I is an elevational view of a toothand is generally illusitrative .of the mode of use of my orthodonticanchorage; Figure II is an elevation taken at the leaving end, showing adie arrangedfor the drawing of both the tubing and the shaftingconstituting the anchorage of my invention; Figure III .is across-sectional view through the die-on .the line IIIIII of Figure II;Figure IV is a cross-sectional view through the ,die on the-line.IV-IV,of FigureII; Figure V is an isometric "yieyvbf the stripused in making the tubing or sheath, .on a greatly enlarged scale,showing the .Strip prior :toits formation into a tube; Figure is anisometric view of the tube as formed ,trom the strip shown in Figure V,on the same scale as Figure V; Figure VII is a perspective .view of the.shafting which fits the tubing of Figure and Figure VIII is anelevation taken ;at right angles to the plane of Figure 1, showing atooth, z-having thereon a band and a complete .plug .and sheath assemblyprovided by cutting fitting together .short pieces of the tubing andshafting.

Referring toFigure ,I .of the drawing, reference numeral I designates;a:molar to which a band 2 is applied. .An ,archwire 3 is to beconnected with the band 2 in such manner that it :may the readilyremoved for adjustment during :the long-continued .process of toothstraightening. Attached to 'the band 2zis a sheath 4 which receives aplug, soldered, or welded, terminally to the arch wire 3. It may benoted initially that the band :2 lies upon, or closely adjacent, thesoft gingival tissue :5 surrounding the tooth I, and that the sheath 4also rests upon the soft tissue. As explained, it is practicallyprohibitive in :guantity manufacture to make either the :sheathd or theplug of matching complex cross- .sectional ,contour if plug members andsheath .members he made individually. For this reason I have so designedthe sheath and plug that they :may be drawn in extended lengths, forsubsequent subdivision ,into pieces of the proper size .ioruse.

In providing these lengths of tubing and of 'shafting, I use'a die 6,having therein drawing apertures .for the tubing material I, la, 1b, 1c,1d, :and having .drawing apertures for the shafting 58., 8a, 8b., 8c,8d, and Be. .In drawing of the tubing ;material, I :may take a fiat, orroughly formed, strip of metal of suitable composition for the ultimatepurpose, and, by drawing it successively through the apertures from 7 to1d, obtain an elongate, thin strip 9 of worked metal, having thereonmarginal upturned flanges I0 and a longitudinally-extending rib I l,disposed centrally of the strip. Figure V of the drawing, show- .ing thefinished strip on a greatly enlarged scale, is provided with dimensionlines for the purpose of illustrating the fineness of the sizinginvolved, and not on the assumption that the exact dimensions shown arenecessary to success. Thus the dimension lines A represent .0145 inch,the dimension jlines B, .0856 inch, the dimension lines 0, .018 inch,and the dimension line D, .028 inch.

In die 6 a length of wire, which may initially be round, of a suitablemetallic alloy is drawn first through the drawing aperture 8, andsuccessively through the other drawing apertures from 8a to Be.

When thus drawn, the result is a length of shafting I2, conforming ingeneral cross-sectional contour to the letter H, but with its two legsI20. converging to one side of the crossbar lZb and diverging on theother side of the crossbar. This shafting also is worked down byelongation to the desired size and contour, and when suitable alloyknown'in the art is employed, the working does not impair the quali tiesof the metal constituting the shaft, or that constituting the tubing.

The tubing l3, which is to provide sheaths, or sockets, 4, receivingplugs 'cut from shafting I2, is formed by passing the finished strip 9through suitable forming dies, which form it into a tube. In the tubestructure, as shown in Figure V of the drawing, the longitudinally andcentrally disposed rib l I forms a longitudinal-rib 4a within' theinterior of the tube, and the outer faces of the marginal flange or ribsID are brought into' abutting relation, so that they also form anopposed longitudinally-extending rib 4b in the 7 interior of the tubing;It will 'be noted that both the rib 4a and the rib 4b have sidesinclined inwardly of the tube. In forming the tube it is constrictedtoward the wall opposite that at which its edges are brought intoabutment. This constriction, which gives an interior contour matchingthe cross-sectional contour of the shafting, and increasing theinterlocking effect between the shafting and the tubing, also permitsthe corners of the tubing to be smoothly curved, and preventsirregularities in the wall thickness of the tubing. .As shown, the sidewalls of the tubing have an inclination of approximately sixteendegrees.

In preparing the anchorage for use, a length of the tubing is cut off,to provide a socket or sheath member Land is attached as by-soldering,or welding, to the band 2, with its'more extended face lying .againstthe band] A plug l4 7 of suitable length is cut from the shafting l2,and the arch wire I3 is attached as by soldering or welding to'the upperend of this plug, prior to insertion of the plug in the socket or sheath4. V The lower end of the socket or sheathis specially prepared for useby cutting it away angularly, so that an edge I5 is'provided at the wideface of the socket which is attached to the band 2. The edge I5' mayenter the space which lies normally between the tooth structure and thesoft tissue, with the angular, or slightly curved, lower edge of thesocket resting on the tissue without penetration. This exteriorcontouring of the sheath is of value in preventing irritation of thesoft tissue.

It should be" understood that the relatively great surface engagementbetween the plug and sheath frictionally engages the plug in the sheathin a manner to prevent accidental dissions as great as is possible inapparatus of such minute overall cross-sectional area. It is, further, acontour, which, as explained above,-permits the forming of the sheathmaterial in lengths of tubing, and the formation of the plug -materialin lengths of shafting for subsequent subdivision. I

Although the plug is of complex cross-section and the sheath or socketconforms interiorly to such contour, the exterior of the sheathor socketis smooth and rounded. It therefore does not tend to irritate thetongue, or other tissue, in

It may be contact with which it may come. noted further that theinterlocking complexity of the sheath or socketand the plug is obtainedby an interior deformation of the socket wall, a

the socket is that a slightly oversize socket may be tightened on ashaft bylight blows or pressure. This is due to the positioning of theseam in the tubing, and the presence of the abutting dividing the socketinto spaced chambers with a connecting passageway between themand a plugmember of a size to pass into'the open-end of the socket, said plugmemberhaving spaced.

longitudinal portions and a reducedneck portionconnecting the same, saidportions fitting snugly in the chambers and passageway respectively andengaging the walls thereof with suificient frictional engagement to holdthe plug member against normal accidental displacement;

2. In an orthodontic anchorage, a' socket mem! ber comprising a basewall-for attachment to a tooth-embracing band, an outer wall of lesswidth than the base wall and side walls that transverse- ,ly convergefrom the base to the outer 'wall, said walls being integral, and theouter and sidewalls being smooth and unbroken and with rounded edges attheir junctions, said walls defining an internal open ended socket, thesaid base and outer walls having opposing inset longitudinal ribs spacedapart and dividing said socket into outer chambers that are transverselytapered with a connecting passageway between them that extends betweenthe ribs,-and a plug member of a size topass into the open end of thesocket, said plug member having spaced longi- 3. In an orthodonticanchorage, a socket mem-.

ber formed from a strip having a central and marginallongitudinallydisposed ribs, said strip having its free edges in juxtaposition to forman open ended socket, the side margins of the 7 strip constituting aseamed base Wall adapted to be attached to a tooth-embracing band, saidmarginal ribs being inset into the socket in juxta-r position to eachother to formin effect a single rib, and the central rib being insetinto the socket in opposition to the marginal ribs and spaced therefrom,thereby dividing the socket into outer chambers and a passagewayconnecting the same between the ribs, and a plug member that enters theopen end of the socket and has a cross sectional contour substantiallycorresponding in size and shape to the socket and having its variousfaces frictionally engaging the corresponding faces of the socket wallsto be thereby maintained in the socket, the outer face of the socketmember being smooth and unbroken and the plug member having an exposedend for attachment to an arch wire.

4. In an orthodontic anchorage, a socket member formed from a striphaving a central and marginal longitudinally disposed ribs, said striphaving its free edges in juxtaposition to form an open ended socket, theside margins of the strip constituting a seamed base wall adapted to beattached to a tooth-embracing band, said marginal ribs being inset intothe socket in juxtaposition to each other to form in effect a singlerib, and the central rib being inset into the socket in opposition tothe marginal ribs and spaced therefrom, thereby dividing the socket intoouter chambers and a passageway connecting the same between the ribs,the opposing side walls of said socket member springing from the basewalls being outwardly convergent and the inner faces of the socketchamber being correspondingly convergent, and a plug member that entersthe open end of the socket and has a cross sectional contoursubstantially corresponding in size and shape to the socket and havingits various faces frictionally engaging the corresponding faces of thesocket walls to be thereby maintained in the socket, the outer face ofthe socket member being smooth and unbroken and the plug member havingan exposed end for attachment to an arch wire.

5. In an orthodontic anchorage, a socket member comprising a base wallfor attachment to a tooth-embracing band and a smooth unbroken outerwall extending from one side to the other side of the base wall anddefining therewith an internal socket having an open end, at least oneof the said walls having an inset longitudinal rib projecting from theplane of the Wall into the bore of the socket to provide in the bore ofthe socket a constriction not represented on the outer surface of thesocket, and a plug member of a size to pass into the open end of thesocket, said plug member having a longitudinal indentation matching thelongitudinal rib in the bore of the socket and flanges formed by saididentation embracing the sides of said rib, said plug member fittingsnugly in the socket and engaging the walls of the socket and rib withsuficient frictional engagement to hold the plug against normalaccidental displacement.

RUSSELL E. IRISH.

